Many machines have been developed for excavating trenches. One commercially available type of machine often used for a trenching operation is a backhoe. Generally, a backhoe is mounted on a tractor or other machine moveable along the ground on wheels or tracks. The backhoe may be the only excavating assemblage or earth handling implement on the tractor or machine, or it may be one of a plurality of implements. For example, one relatively common machine, generally known as a backhoe loader, may include a backhoe mounted at one end of a tractor, and may include a loader bucket and accompanying operating linkage mounted at the other end of the tractor.
A typical backhoe may include a boom, a stick, and a bucket. In general, the boom may be pivoted to the machine for movement in a generally vertical plane, the stick may be pivotally mounted to the boom for movement in the same generally vertical plane, and the bucket may be pivotally mounted to the stick. Each of the boom, stick, and bucket may be moved about a pivotal connection by one or more actuators, such as hydraulic cylinders. The entire excavating assemblage of boom, stick, and bucket may be mounted on the machine for swinging movement in a generally horizontal plane.
In excavating a trench, the operator of a machine, such as a backhoe, manipulates the machine controls to cause the boom, stick, and bucket to move in coordination such that the bucket digs into the earth generally along the direction of extent of the trench. The bucket is moved about its pivot to become filled with earth, the filled bucket is held in a curled position and lifted by coordinated movement of the boom and stick from the trench being formed, and the assemblage of boom, stick, and bucket is then swung away from the trench for dumping, either into a pile adjacent the trench, or into a waiting container or carrier, such as a dump truck.
Another machine which also features an implement similar to a backhoe is generally known as a hydraulic excavator. The hydraulic excavator has several features in common with the backhoe of a backhoe loader, except that the boom, stick, and bucket assemblage of the hydraulic excavator does not swing in a horizontal plane relative to the machine. Rather, in a hydraulic excavator, the entire upper body of the machine rotates relative to the lower body or undercarriage. By rotating the entire upper body, the angular position of the boom, stick, and bucket about a vertical axis and relative to the worksite is adjusted.
During the process of lifting the filled bucket from the trench being formed, and/or during the process of swinging the assemblage to the off-loading position for dumping, a portion of the excavated earth may fall along the edge of the trench as “off-fall.” This loose material along the edge of the trench, or off-fall, may fall back into the trench, either during the process of excavating the trench, or subsequently when other activities occur adjacent and/or within the trench.
If off-fall reenters the trench before access to the trench is lost, the problem may be resolved, and the off-fall removed, by reexcavating to remove the off-fall that has reentered the trench. Such reexcavating may be accomplished by the same machine employed in excavating the trench. Alternatively, reexcavating may be accomplished by a different machine. However, reexcavating, whether by the same machine, a different machine, or even manually, may result in inefficiencies, such as increased time, labor, and expense.
If the off-fall reenters the trench during concrete pouring, or shortly after concrete is poured and not yet cured, the off-fall may foul the concrete. This may weaken the concrete or, if on the surface of the concrete, it may require careful, manual removal of the soil. Whether off-fall reenters the trench during the process of excavating, or whether it is dislodged into the trench by subsequent activities, removal of the off-fall necessitates additional time and labor and results in decreased productivity. If the off-fall is merely left in the trench where it falls, or if it becomes mixed with poured concrete, the result is decreased quality of work. Some efficient manner of controlling the adverse consequences of loose off-fall would be both beneficial and desirable.
A backhoe with an attached compacting roller is disclosed in U.S. Pat. No. 4,974,349 issued to Timmons. In the Timmons patent, a compacting roller is attached to the back of the backhoe bucket. The compacting roller may be used for compacting material in the trench being excavated. The compacting roller may remain attached to the bucket while the bucket is used for excavating.
While the arrangement in the Timmons patent may be useful for compacting material within the trench, the Timmons patent does not disclose controlling, removing, or compacting off-fall, much less automating off-fall removal or compaction. Furthermore, the compacting roller is an additional element that may increase cost and require assembly and disassembly.
Off-fall adjacent the trench edge may be cleaned manually or by a machine under operator control. However, both manual cleaning and cleaning by machine under operator control may result in inefficiencies. Manual cleaning is time consuming and may increase labor costs. Cleaning by machine under operator control may require a high level of skill may result in inaccurate work, including incomplete removal of off-fall.
The disclosed off-fall control method and system are directed toward improvements and advancements over the foregoing technology.